The invention relates to a mirror and is particularly, but not exclusively, concerned with a mirror made of a synthetic plastics material to be mounted on a pivotally-mounted sun visor of a motor vehicle. Such a mirror is usually called a vanity mirror. Alternatively the mirror may be an interior rear-view mirror for use in a motor vehicle.
Vanity or interior rear-view mirrors have been made hitherto of silvered glass but these are dangerous as they can easily be broken by impact by a person, usually the front passenger or the driver, in a vehicle involved in a collision.
Mirrors have been made of a synthetic plastics material, for example an acrylic resin, which is metallised on its rear surface by vacuum deposition or other metallising process. Plastic mirrors are not readily broken and if they do break will not splinter into sharp pieces like a glass mirror.
Recently regulations have been promulgated making it necessary for fittings and parts in a region of a motor vehicle where they could be impacted by the head of the driver or a passenger in the event of a collision to have a rounded edge of a minimum radius. Currently this minimum external radius is 3.20 mm. A typical plastic mirror has a thickness of only approximately 2 mm. and so it is not possible to produce a rounded edge with a radius of at least 3.20 mm. Increasing the thickness of the mirror to 3.20 mm. or more over the whole area of the mirror would not be practicable as the mirror would be thick and therefore brittle. Also the manufacture of the mirror would be too costly as the quantity of material used and also the time taken to mould the mirror would both be prohibitively increased.